Kidney Disease
Kidney diseases include a spectrumof disorders characterized by abnormalities of kidney structure or function that have implications for health.[1] The two major categories of kidney disease are (1) chronic kidney disease (CKD), defined as persistent impairment in kidney function, and (2) acute kidney injury (AKI), defined as a sudden loss in kidney function (Table 26.1). The prevalence of both CKD and AKI increases with aging, and more than half of all patients with kidney disease are over the age of 65 years.[2,3] While CKD is often asymptomatic early in the course of disease, later stages are associated with health implications related to the loss of key kidney functions: filtration and urine production, maintaining fluid and electrolyte balance, acid-base homeostasis, calcium and vitamin D metabolism, and stimulation of red blood cell production. In addition to morbidity related to direct loss of kidney function, among older adults kidney disease has been linked to higher rates of mortality, cardiovascular disease (CVD), and geriatric conditions.
